Need help with firewall security ...
Hello. I have a question about securing a server ad forwarding some ips
I have a computer connected to the internet using IP eg: 18.104.22.168 and I have a 32 IP subnet - eg 22.214.171.124 with netmask 255.255.255.224 (this means that I can use 126.96.36.199 for braodcast and IPs from 188.8.131.52 -> 184.108.40.206)
The "server" has 2 ethernet cards: eth0 with IP 220.127.116.11 and eth 1 with 18.104.22.168.
I set /proc/sys/net/ipv4/ip_forward to 1 - this ensures the IP forwarding from and to the copmuters in the 22.214.171.124 subnet.
My questions are the following: do I need to add any other line in the firewall configuration, for the computers in the subnet to have access to the internet ?
How can I secure my server from outside attacks and not cut off the internet access for the other computers ?
Please help me with this = I am really new to this thing and I would really like to know a "professional"s idea about this